> > prove what? > > if the machine with an rDNS of bobhoffman.com sends mail from > <*@bobhoffman.com>, and is the MX of this domain, would anybody think > this is a forgery? > Mouss... I mean Ratatouille :-) Answer: Possibly Depends on many factors doesn't it? I know you are on other lists like SA so I am not sure why you are leading us down the infinite possibilities path... ...seeing as you are quite excellent at *nix and *net administration and implementations. :-) - rh